iPhone game developer Nimblebit is accusing Zynga of ripping off its popular mobile title, Tiny Tower. Last week the company launched Dream Heights, a free tower-building game for iOS with in-app purchases that shares a number of similarities to Nimblebit's Tiny Tower. The popular iOS tower building game received Apple's 2011 iPhone Game of the Year.

Nimblebit's Ian Marsh got his point across about the similarities between the two games by releasing an image via Twitter. The image puts the two games side-by-side for comparison.

"We noticed you are about to launch a new iPhone game called Dream Heights! Congratulations!" reads the image, which was addressed to "all 2,789" of Zynga's employees. "We wanted to thank all of you guys for being such big fans of our iPhone game of the year, Tiny Tower!"

The comment continues: "Good luck with your game, we are looking forward to inspiring you with our future games! Sincerely, (all 3 of us) -- Nimblebit."

Marsh also noted on Twitter that Zynga "did try to go the honest route and try to acquire us first." He added that inside Dream Heights' app binary, the Zynga project "is named 'TowerVille' and its inhabitants are named zitizens" -- Tiny Tower's are called "bitizens."

It's not clear what Nimblebit plans to do going forward, other than attempting to call Zynga out for what it perceives as out-and-out theft. Certainly the comparison of these two games make Zynga look a bit hypocritical because they have sued several companies for copying some of their popular Facebook games.